My toddler gets a lazy latch sometimes too, and I get teeth marks but luckily no pain. If your dd is slipped off the nipple so far that her teeth touch the nipple not the areola, I wouldn't hesitate one second to unlatch her and ask her to nurse nice. Ds is the same age as your dd and he gets it when I say, nurse nice, open big. He sometimes lets the nipple slip and gets it just behind his front teeth which pinches and chafes me, I treat it same as biting and insist gently that he must latch on right or we will take a break and try again later.
I reduced those looong bedtime nursing sessions by using the Pantley pull-off to get ds to unlatch earlier. It was not a quick fix, it took a few weeks and some nights he would not accept it til I had tried many times, but by the third week he would let go at the touch of my finger without waking. Then I could put him down. I am glad I did that because now he has become able to unlatch earlier and earlier, he will now nurse for 15 min and I can put him down drowsy but awake enough to grab his lovie and blanky and say goodnight.
During the day I will let him go on for longer sessions but there are times like when AF is due that I can't tolerate it going on and on. I use a song or rhyme to measure out how much time he has left, I'll tell him we'll stop when the song is over.
I don't really have any insight into dealing with the new nightwakings, maybe she is teething? Ds is showing signs of it right now, he's drooling constantly.
I know how frustrating it can be, and I think if you can find a way to take the pressure off a little, you'll feel relieved and be able to find a middle ground that meets both your needs and your dd's so that you can reach your goal of CLW. I think we all have to make little adjustments along the way or we'd get so fed up and overwhelmed we'd never make it. hope things improve for you.